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The majority of atypical teratoid/rhabdoid tumors (ATRTs) appear as heterogeneous masses with solid, cystic, necrotic components and calcification in the cerebral hemispheres; however, acute hemorrhagic onset is rare. The aim of this study is to describe a patient with an acute hemorrhagic supratentorial ATRT. A 4-year-old patient presented with right-sided weakness, nausea, vomiting, and loss of consciousness. Cranial magnetic resonance imaging revealed a large solid and cystic mass in the left posterior frontotemporal region with evidence of acute hemorrhage. The patient underwent urgent surgery, and gross total excision of the hemorrhagic tumor was achieved. A follow-up brain magnetic resonance imaging performed 2 months after surgery showed no evidence of tumor recurrence. Although hemorrhage is not uncommon in ATRT, massive acute hemorrhagic onset may obscure the underlying neoplasm; therefore, ATRT should be included in the differential diagnosis of spontaneous supratentorial hemorrhage in children.

Background: Endoscopic endonasal approach (EEA) has become a well- established approach for skull base pathologies, providing a minimally invasive corridor to access various lesions. While the technique has been extensively studied for common skull base tumors, data on extremely rare pathologies remain limited. Our study aims to present our experience with rare skull base lesions managed via the endoscopic endonasal approach, highlighting the challenges associated with preoperative diagnosis, intraoperative decision-making, and surgical strategy modifications. Methods: A retrospective analysis was conducted on patients who underwent endoscopic endonasal surgery at the tertiary center up to January 2025. Among 6,225 endoscopic endonasal procedures performed, 41 patients with exceptionally rare skull base pathologies were identified. Each tumor type was separately evaluated for differences in resection rates, complication rates, and recurrence patterns. Results: These included 6 pituitary pituicytomas, 5 plasmacytomas, 5 xanthogranulomas, 4 granular cell tumors, 3 giant cell tumors and others. Gross total resection was achieved in 68% of cases, with subtotal resection in vascular or malignant tumors. Intraoperative challenges included unexpected vascularity and fibrotic adhesions. Postoperative CSF leakage occurred in 7%, and recurrence was observed in 17%, mostly in malignant or partially resected tumors. No intraoperative mortality was recorded. Tailored adjuvant treatments ensured durable disease control in most patients. Conclusions: Even in highly experienced centers, rare skull base pathologies pose unique diagnostic and surgical challenges. The discrepancy between preoperative and intraoperative findings often necessitates real-time strategic adaptations. In these rare cases, for optimizing patient outcomes requires a comprehensive understanding of skull base anatomy, flexibility in surgical planning, readiness for sudden strategy modifications, and a multidisciplinary approach.

A bstract: With the rise of digital pathology, integrating digital slides with deep learning–based decision support systems is becoming increasingly common in clinical practice. Tissue region segmentation which is distinguishing tissue from background/artefacts, is an important pre-requisite in many digital pathology pipelines both for the laboratories as their first step in digitalizing the glass slides of tissue samples and turning them to whole slide images (WSIs) using scanners, and also for DL researches such as region-of-interest cropping, tumor detection, cell segmentation. However, it is well known that WSI scanners can fail in detecting all tissue regions, due to the tissue type, or due to weak staining and this is because of their not robust enough tissue detection algorithms which makes segmentation of WSIs a challenging task. Hence, this study develops a fast, lightweight, accurate, CPU-ready DL approach, enabling fast and reliable tissue region segmentation model by training and testing it across seven different institutional H&E and IHC stained WSIs to result a strong in generalization with the 22 to 56 s/WSI inference time using CPU that markedly outperforms classical OTSU thresholding, particularly in preserving challenging or faint tissue regions by achieving notably higher and more consistent performance than OTSU, with median Jaccard and Dice scores of approximately 0.86 and 0.92, respectively, compared to OTSU whcih was between 0.56 and 0.72. Our approach provides a practical, open-source solution for resource-limited pathology settings. We publicly released dataset obtained from Bahcesehir Medical School, and code to foster benchmarking and further advances in efficient, deployable computational pathology. The model could be used in digital slide scanners to improve the scanning process and in the pre-processing stages of DL pipelines to prepare high-quality datasets.

Carcinoid tumors, originating from neuroendocrine cells, are slow-growing tumors that are predominantly found in the gastrointestinal tract and bronchopulmonary system. Surgical resection is the primary treatment for localized tumors. However, the long-term risk of recurrence, including rare cases of metachronous tumors, presents an ongoing clinical challenge. This case report details a 77-year-old male who underwent lobectomy for a pulmonary carcinoid tumor and later developed contralateral recurrence after 7 years, emphasizing the importance of surveillance strategies in such cases.

Invasive aspergillosis is a rare but severe fungal infection primarily affecting immunocompromised individuals. The Coronavirus Disease-2019 (COVID-19) pandemic has introduced new complexities in managing aspergillosis due to the widespread use of corticosteroids for treating COVID-19-related respiratory distress, which can increase susceptibility to fungal infections. Here, we present a challenging case of progressive cerebral aspergillosis complicated by cavernous sinus thrombosis (CST) in a 67-year-old male with a history of COVID-19. The patient, initially misdiagnosed with temporal arteritis, received pulse corticosteroid therapy twice before presenting with persistent left-sided headaches and vision loss. Cranial imaging revealed findings consistent with fungal sinusitis, Tolosa–Hunt syndrome, and orbital pseudotumor, which progressed despite initial antifungal therapy. Subsequent magnetic resonance imaging indicated an invasive mass extending into the left cavernous sinus and other intracranial structures, raising suspicion of aspergillosis. A transsphenoidal biopsy confirmed Aspergillus infection, leading to voriconazole therapy. Despite aggressive treatment, follow-up imaging revealed significant progression, with extension to the right frontal region and left cavernous sinus. The patient then developed visual impairment in the right eye and was diagnosed with CST secondary to fungal sinusitis. Management included a combination of systemic antifungals and antibiotics; however, the patient declined surgical intervention. This case underscores the diagnostic challenges and rapid progression associated with cerebral aspergillosis in post-COVID-19 patients treated with corticosteroids. This report highlights the need for heightened clinical suspicion and prompt, targeted interventions in similar cases to improve patient outcomes. Further research is required to understand the optimal management of invasive fungal infections.

Teratomas typically arise as midline lesions in the suprasellar and pineal regions. Pneumosinus dilatans is a rare condition characterized by the expansion of one or more of the paranasal sinuses and thinning of their bony walls with a normal covering mucosa. It usually involves the sphenoid and posterior ethmoid sinuses and has been associated with meningiomas and arachnoid cysts. Off-midline mature teratomas are uncommon, and no reports have described an association with pneumosinus dilatans. We present a rare association between an intracranial off-midline mature teratoma and pneumosinus dilatans in an 18-year-old male patient who presented with a second episode of a left-sided seizure, which has not yet been reported in the literature.

Aim We aimed to describe the computed tomography (CT) and magnetic resonance (MR) imaging findings of intracranial extra-axial chondroma. Material and methods We retrospectively evaluated the imaging findings of CT and MR examinations of six patients (three men and three women, aged 21–66 years) with histopathological diagnoses of intracranial extra-axial chondroma. Results Four tumors were located in the frontal region and two in the cavernous sinus. All the tumors showed low signals on diffusion-weighted images and high signals on apparent diffusion coefficient maps without restricted diffusion. There was no perifocal edema in all the tumors. Cavernous sinus chondromas were associated with bone erosion and anterior displacement of the internal carotid arteries, but without calcification. Calcification was present in all frontal chondromas. All the tumors revealed low signals on T1-weighted MR images. Frontal chondromas revealed mixed signals, but cavernous sinus chondromas were brightly hyperintense on T2-weighted MR images. No enhancement was detected in the two chondromas. An intense homogeneous enhancement was detected in a cavernous sinus chondroma. Conclusion The imaging appearances of frontal extra-axial chondromas and cavernous sinus chondromas may have different imaging appearances. Although there is a wide range of imaging findings, the absence of restricted diffusion, perifocal edema, enhancement, and presence of low signals on T1-weighted MR images in a well-circumscribed calcified extra-axial mass should suggest an intracranial chondroma.